Extrusion die

ABSTRACT

This invention has to do with an extrusion die in which a plunger enters a closed die in one direction and forces metal laterally through a forming element and an exit opening.

United States Patent Heitman et al.

[ 1 Sept. 19, 1972 EXTRUSION DIE [72] Inventors: George H. Heitman, Shrewsbury; Eric T. Strom, Holden; Anthony G. Cerrone, Worcester, all of Mass.

[73] Assignee: Wyman-Gordon Company, Worcester, Mass.

[22] Filed: Oct. 26, 1970 [21] Appl. No.: 83,867

[52] U.S. C1,; ..72/272, 72/467 [51] Int. Cl ..B2lc 27/00 [58] Field of Search ..72/467, 272, 264, 269, 263

[56] References Cited UNlTED STATES PATENTS 3,059,768 10/ 1 962 Altwicker et al. ..72/272 3,230,759 l/ 1966 Schoenfield et al. ..72/467 2,964,178 12/1960 Goldsmith et a1. ..72/263 2,960,221 11/ 1960 Albers et a1. ..72/272 3,279,230 10/ 1966 Johnson ..72/263 Primary ExaminerRichard J. Herbst Attomey-Norman S. Blodgett [5 7] ABSTRACT This invention has to do with an extrusion die in which a plunger enters a closed die in one direction and forces' metal laterally through a forming element and an exit opening.

6 Claims, 3 Drawing Figures PATENTEDSEP 19 m2 SHEET 1 0F 3 GEORGE H. HEITMAN ERIC 7. STROM ANTHONY 6. CE RRONE INVENTORS.

EXTRUSION DIE BACKGROUND OF THE INVENTION In the formation of metal articles and, particularly, extruded pieces of titanium, it has been common practice (as demonstrated in Gersman U.S. Pat. No. 2,750,034) to force the metal through a formed nozzle. The machines for carrying out this extrusion process have been very expensive and have been limited to the single use as an extruding apparatus. Furthermore, as the need for larger cross-sections of extruded titanium has developed, the size of the machine has caused other problems including an increase in cost and the need for a large area in the plant. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of the invention to provide an extrusion die, making use of a conventional vertical press for extruding metals such as titani- Another object of this invention is the provision of apparatus for extruding metals in which the forming element may be readily replaced.

A further object of the present invention is theprovision of apparatus for extruding metals into a wide form, which apparatus is inexpensive and occupies relatively little space.

It is another object of the instant invention to provide an extrusion die in which the formed element may be readily removed after each extrusion and replaced with a reconditioned forming element.

A still further object of the invention is the provision of an extruding die for producing extremely wide extruded titanium articles.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

SUMMARY OF THE INVENTION In general, the invention consists of an extrusion die for use with a press having a base with a mounting surface and a plunger operative to move in the direction of its length toward and away from the surface at a right angle thereto, having a main body adapted to be mounted on the surface, and having an interior chamber. The body has a passage into the chamber in which the plunger slides and has an exit opening extending from the chamber laterally of the direction of movement of the plunger. A forming element is located in the chamber and provides a formed passage for the flow of metal from the chamber through the exit opening under compression from the plunger.

More specifically, the forming element fits snugly into the bottom of the chamber in opposition to the said passage and is formed with a primary cavity underlying the passage and a forming cavity extending from the primary cavity to the exit opening.

BRIEF DESCRIPTION OF THE DRAWINGS The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:

FIG. 1 is a perspective view of an extrusion die embodying the principles of the present invention,

FIG. 2 is a sectioned exploded view of the-die, the section beingtaken on the line lI-lI of FIG. 1, and

FIG. 3 is a perspective view of an article formed with the die of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, wherein are best shown the general features of the invention, it 'can be seen that the extrusion die, indicated generally by the reference numeral 10, is intended for use with a press 11, having a mountingsurface l2'and a plunger 13 which is operative under tremendous pressure to move in the direction of its length toward and away from the surface 12 and at a right angle thereto. A die is provided having a main body 14 adapted to be mounted on the surface 12 and having an interior chamber 15 (see FIG. 2). The body 14 has a vertical passage 16 in which passage the plunger 13 slides. The chamber is provided with a horizontal exit opening 17 extendingflfrom the chamber laterally of the direction of movement of the plunger. A forming element 18 is located in the chamber 15 and provides a formed passage 19, so the metal flows from the chamber 15 through the exit opening 17 under compression from the plunger 13.

Theplunger 13 has a generally rectangular head 21 formed on a shank 22of reduced cross-section. The

passage 16 has the same cross-sectional shape as the head to provide a close sliding fit. The body 14 is formed in two parts, 23 and 24, joined along a parting line 25'that is parallel to the said mounting surface 12 of the base 11 of the press.

As is evident in FIG. 2, the passage 16 extends entirely through the upper part 23 of the body and the chamber 15 is entirely formed in the lower part 24. The forming element 18 fits snugly into the bottom of the chamber 15 in opposition to the said passage 16. The forming element is formed with a primary cavity underlying the passage and a forming cavity 19 extending from the primary cavity to the exit opening 17.

The forming cavity has the cross-sectional shape of a structural member similar to the member 27 shown in FIG. 3; that is to say, having a web 28 from which extends flanges'29 and 31, whose edges are provided with beads 32 and 33, the flanges extending at right angles to the web. A web portion of the forming cavity 19 has the dimensional thickness of the web for a short distance only (indicated by the dimension A--A in FIG. 2) from the primary cavity 26 and then expands to a depth substantially greater than the thickness of the web for the remainder of the distance to the exit opening 17. The forming cavity 19 is coated with a ceramic material such as glass, applied by use of the flamespraying technique.

The use of the apparatus will now be readily understood in view of the abovedescription, The forming element 18 is flame-sprayed with a ceramic coating before each extrusion operation. It is then placed in the bottom of the chamber 15 of the bottom part 24 of the die and a billet of the selected metal is placed in the chamber 15. The top part 23 of the die is placed on the bottom die and the die is heated to a temperature in the range from 700 to 800 F. The die is then placed in the press 11, the plunger 13 is placed in the press also, and and press is moved downwardly into the passage 16 and forced into the chamber or cavity 15. The metal passes through the passage formed by the forming element 18, I

is plastically formed into the desired shape, and leaves the die through the exit opening 1-7. As soon as the metal extrusion has been completed, the die isopened and the extrusion and the forming element 18 are removed. It is usually necessary to remove the extrusion or product from the forming element 18, and this is done at a location away from the press. In the meanwhile, another forming element is placed in the chamber and the process repeated. The old forming element is processed by cleaning it and coating the surface with ceramic once more; it is then ready for reuse.

The advantages of the invention are obvious from the description. The use of large titanium structural extrusions has increased during the last few years but, due to the limitations of extrusion press capacity for titanium (both as to tonnage and size), the largest extrusions that could be made have been approximately 22 inches wide. Furthermore, the maximum extrusion press tonnage has been about 12,000 tons. However, it is desirable, from the standpoint of economic consideration in aircraft design, that extrusions in the area of 30 to 36 inches wide be made to lessen the weight of the aircraft and increase the structural integrity of the aircraft structures. By use of the present invention, it is possible to obtain extrusions much wider than 22 inches and made on existing forging equipment that will reach a maximum force of 50,000 tons. By use of the present apparatus, it is feasible to employ the side extrusion technique to produce a new product that can be used by designers of advanced aircraft. No new type of press needs to be designed and built and, by use of the present apparatus, it is possible to assure that the forming elements are not only accurate but adequately protected during the extrusion. In the past, one of the difficulties with extrusion techniques has always been that the nozzles wore out rapidlybut, by use of the ceramic coating, not only is wear on the guiding surfaces prevented, but the ceramic guarantees that the forming element can be removed from the die cavity quite readily. Furthermore, the apparatus does not remain idle while the renewal of the forming elements is taking place.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been .thus described, what is claimed as new and desired to secure by Letters Patent 1. An extrusion die for use with a press having a base with a mounting surface and a plunger operative to move in the direction of its length toward and away from the surface at a right angle thereto, comprising:

a. a main body adapted to be mounted on the surface and having an interior chamber, the body having a passage into the chamber into which the plunger slides and having an exit opening extending from the chamber of the direction of movement of the plunger, the chamber having an integral bottom facing the said passage, the said passage and the said opening being the only openings into the zi r r n irig lement located in the chamber and providing a formed passage for the flow of metal from the chamber through the exit opening under compression from the plunger, the forming element fitting snugly into the bottom of the chamber in opposition to the said passage and being formed with a primary cavity underlying the passage and a forming cavity extending from the primary cavity to the exit opening.

2. An extrusion die as recited in claim 1, wherein the plunger has a generally rectangular head supported on a shank of reduced cross-section, and wherein the said passage has the cross-sectional shape of the head for a close sliding fit.

3. An extrusion die as recited in claim 1, wherein the body is formed in two parts and joined along a parting line that is parallel to the said mounting surface of the base.

4. An extrusion die as recited in claim 3, wherein the passage extends entirely through one part and the chamber is formed in the other part.

5. An extrusion die as recited in claim 1, wherein the forming cavity is in the shape of a structural member having a web from which extends at least one flange at a right angle to the web, and wherein the web portion of the forming cavity has the dimension of the web for a short distance only from the primary cavity and then expands to a depth substantially greater than the thickness of the web for the remainder of the distance to the exit opening.

6. An extrusion die as recited in claim 1, wherein the formed passage is coated with a ceramic material applied by use of the flame-spraying technique.

a a a s 

1. An extrusion die for use with a press having a base with a mounting surface and a plunger operative to move in the direction of its length toward and away from the surface at a right angle thereto, comprising: a. a main body adapted to be mounted on the surface and having an interior chamber, the body having a passage into the chamber into which the plunger slides and having an exit opening extending from the chamber of the direction of movement of the plunger, the chamber having an integral bottom facing the said passage, the said passage and the said opening being the only openings into the chamber, and b. a forming element located in the chamber and providing a formed passage for the flow of metal from the chamber through the exit opening under compression from the plunger, the forming element fitting snugly into the bottom of the chamber in opposition to the said passage and being formed with a primary cavity underlying the passage and a forming cavity extending from the primary cavity to the exit opening.
 2. An extrusion die as recited in claim 1, wherein the plunger has a generally rectangular head supported on a shank of reduced cross-section, and wherein the said passage has the cross-sectional shape of the head for a close sliding fit.
 3. An extrusion die as recited in claim 1, wherein the body is formed in two parts and joined along a parting line that is parallel to the said mounting surface of the base.
 4. An extrusion die as recited in claim 3, wherein the passage extends entirely through one part and the chamber is formed in the other part.
 5. An extrusion die as recited in claim 1, wherein the forming cavity is in the shape of a structural member having a web from which extends at least one flange at a right angle to the web, and wherein the web portion of the forming cavity has the dimension of the web for a short distance only from the primary cavity and then expands to a depth substantially greater than the thickness of the web for the remainder of thE distance to the exit opening.
 6. An extrusion die as recited in claim 1, wherein the formed passage is coated with a ceramic material applied by use of the flame-spraying technique. 